That 24.5 Newtons must be supported by the vertical component of the tension in the line on the left.
So T (4/sqrt (4^2+10^2) = 24.5

T = 24.5 (sqrt 116)/4 = 66 Newtons
If this is a mathematics rather than a physics question they may express force in kilograms (mathematicians do stuff like that) in which case divide by g which is about 9.8 m/s^2